James Madden, forecaster for Exacta Weather, added: "There is a chance maximum temperatures could climb as high as 95F (35C) by the end of the week in some parts to the South and South-east. But the high temperatures will also set off storms. In Spain, temperatures this week may reach 42C.

Met Office forecaster Dan Williams said "Spanish plume" was meteorologists' "catchy name for a rather complex set of conditions".

He added: "Our meteorologists are keeping a very close eye on the potential for more widespread thundery downpours on Saturday."